Motor vehicle power transmission



May 23, 1939.

C. BREER MOTOR VEHICLE POWER TRANSMISSION Original Filed Feb. 21, 1934INVENTOR. Carl ,Breen.

ATTORNEYS.

Patented May 23, 1939 UNITED STATES PATENT OFFICE 2,159,310 MoronVEHICLE rowan TRANSMISSION Carl Breer, Grosse Pointe Park, Mich,assignor to Chrysler Corporation, Highland Park, Mich, a corporation oiDelaware Continuation of application Serial No. 712,352, February 21,1934. This application February 28, 1935, Serial No. 8,625

6 Claims.

' pending application Serial No. 712,352 flled Feb-v ruary 21, 1934: v

It is desirable in connection with the drive for motor vehicles toprovide a speed ratio chang- .10 ing transmission for varying thedriving ratio between the engine and vehicle driving' wheels and myinvention is particularly related to motor vehicles having speed ratiochanging transmis- 'fsions of the planetarypr epicyclic gear type. It

= is customary in planetary gear transmissions to provide a plurality ofplanetary gear trains or 7 sets, each planetary gear train having a drumon other element associated therewith for controlling the gear train.These drums' are usually 20 rotated by the respective planetary geartrains when they are not operating to transmit the drive through thetransmission and each drum has a braking device associated therewith andadapted to hold the drum stationary in order to transmit 25 the drivethrough the respective planetary gear trains. A manually operatedselector controlling device is provided for causing selective operationof the various planetary gear sets in order to vary the driving speedratio through the planetary 30 transmission.

In general a planetary-type of transmissionpresents a number ofadvantages over the more conventional sliding gear types oftransmissions. For example, the planetary transmission permits gearchanges without the necessity of releasing the main clutch between theengine and transmission so as to obtain relatively quick gear changesand faster acceleration of; the motor vehicle. This is made possible byreason of the 40 fact that the braking" devices associated with therespective planetary geartrains are in effect clutches in that eachrotary drum controlling a planetary gear train is frlctionally engagedby its associatedbraking means. The aforesaid faster 45 accelerationbetween the gear changes of .a plane! tary transmission may also befurther brought about by reason of the motor speeding up between thegear changes where the engine throttle is not moved toward its closingposition. 5 The planetary type oftransmission has the I furtheradvantage of not requiring a free wheeling clutch in order to obtainsmooth and otherwise satisfactory gear shifting characteristics andsynchronizing devices customarily used on ss more conventional types oftransmissions may also be dispensed with. The planetary type oftransmission provides gear sets which are quiet at all speeds and whichoperate at a higher eificiency than the more conventional countershaittypes of sliding gear transmissions. Furthermore, I!

it is-possible with a planetary gear transmission to manipulate thetransmission into reverse on driving the vehicle down a hill so as toutilize the reverse gearing as a brake, or the transmission may bemanipulated into a lower gear for the 10 same purposes.

Heretofore, it has been customary to provide a main clutch in the formof a fluid coupling for transmitting the drive from the engine to theplanetary gear transmission but the fluid coupling typeof clutch is opento a number of disadvantages. Thus, where a fluid coupling type ofclutch is used, the engine when idling drives the transmission drivingshaft through the fluid medium of the clutch and where the planetarytransmission is left in gear, the vehicle will tend to be slowly drivenand can only be held still when on alevel roadway by manipulating thetransmission to the neutral .setting or by maintaining the vehicle wheelbrakes in the applied or braking position. This requirement for shiftingthe transmissionto neutral occasions a loss in time in getting thevehicle started inasmuch as a further manipulation of the transmissionis required.

A further disadvantage in connection with the planetary geartransmission when employed with a fluid clutch resides in typical coldweather engine starting conditions inasmuch as a residual drag is placedon the engine by reason of the planetary gear sets which tend to preventeasy turning over of the engine through the fluid medium of the clutch.A further objection to the use of a fluid coupling resides in the factthat where his desired to start the engine by push- 4 ing the motorvehicle, the absence of'a direct connection between the ground wheelsand the en gine renders such starting impossible.

It is an object of my invention to provide improved means fortransmitting the power from the engine to a transmission of theplanetary gear type-whereby the aforesaid advantages of the planetarygear transmission may be retained, enlarged upon, and realized to agreater degree, and at the same time to overcome the aforesaiddifflculties incidentto the use of a clutch of the fluid coupling type.A further object of my invention resides in the provision of improvedclutching means for controlling the drive from the engine to a planetarygear transmission wherein '55 which:-

60 trolling devices.

3-4 of "1"ig.,2.

A Q amasm the clutch will be automatically disengaged when the engine isidling so as to thereby remove the when the vehicle is standing still.

In carrying out the objects of my invention, I preferably provide aclutching means which is automaticaly responsive in its actuation to the1 operation of the engine, the clutch being power operated, for example,by the vacuum which is 19 produced by the engine intake system. I amthus enabled to utilize a friction type of clutching means althoughother types of clutching means may be utilized within keeping of theobjects of my invention.

15 Stillfurther objects of my invention reside in i the provision ofimproved clutching means for transmitting the power from the engine tothe planetary gear transmission whereby the motor vehicle can be broughtto a complete standing- 20 still position, the engine being free fromthe transmission and when desired the transmission may be left with oneof its planetary gear sets in its operating condition. Thus, it is notnecessary to manipulate the transmission into the 25 neutral setting'when the motor vehicle is brought to a stop and since under suchconditions one of the planetary gear sets may be left in .its operatingcondition, the motor vehicle may be quickly started. Furthermore, byreason of my 30 invention, the engine is automatically disconnected fromthe planetary gear transmission thereby facilitating engine startingparticularly in cold weather.

A still further object of my invention resides 35 in the provision ofimproved clutching means for controlling the drive from the engine tothe planetary gear transmission wherein a direct ground wheels of themotor vehicle is possible through the intermediary of the transmissionso that the engine can be started by pushing or towing the motor vehiclethereby eliminating one of the aforesaid difliculties incident to theuse of a fluid coupling, type of clutch.

4' My power transmission system is also of advantage in that it occupiesa relatively small spaceprovidingadditional leg room for the occupantsof the motor vehicle and is generally manufacture. ;Further objects andadvantages of my invention will be apparent from the following detaileddescription of one embodiment thereof, reference being had to theaccompanying drawing, in

I .Fig. l'is-asectional elevational view showing my power drivingmechanism, .a portion of the casing offthe planetary gear transmissionbeing broken away tolu'strate the speed ratio con- 1 Fig. 2,is a planview of the driving mechanism illustrated in Fig. 1.

Fig-3 is a sectional elevational view of the main clutch'Q-the sectionbeing taken along the line Referring to the drawing, reference characterA 'representsthe prime mover'which may be in the form 'of the well-knowninternal combustion engine, B representing the main clutch receiv- 70ing the drive from the engine, and C. is the speed ratiocontrolling'transmission having a power take-oil shaft III whichtransmits the 'drive to 1 the usual rear vehicle ground wheels (notshown).

The transmission C is'preferably of the plane- 7 3 tary type and has theusual well-known gear aforesaid drag of the engine of the transmissionconnection between the engine and driving x more desirable and lessexpensive as a matter of ratio speed controlling braking devices II, I2, i3 and II which are respectively adapted to control the first speed,second speed, direct or third speed, and'reverse. In Fig. 1 I havediagrammatically illustrated the braking device l2 associated .with therotary drum I5 operated by the planetary gear train l6, it beingunderstood that the other braking devices for the various speed ratiosmay be similarly arranged in a manner well known in the art. 10

In order to selectively control the actuation of the various speed ratiocontrolling devices, I have illustrated a manually operable selector armI! pivoted at l8 in association with the selector segment I3conveniently mounted on the steering post of the usual vehicle steeringwheel 2|. The segment I 3 has a plurality of notches adapted to receivethearm ll, these notches being designated at 22, 23, 24, and 26respectively adapted to manipulate onset the transmission for the firstspeed gear ratio, second speed, third speed, reverse or neutral. In Fig.1 the arm- I1 is illustrated in the neutral position,

it being understood that in such position the various rotary drumscorresponding to the drum 5 I5, are freely rotatable so as not totransmit the drive through the transmission to the shaft Ill. The arm I!actuates a lever 21,-the latter being pivotaly connected through a link28 to actuate a lever 23 pivoted at 30 intermediate the ends 30 thereof.The lever 29 in turn transmits the movement through a link 3| to thelever 32 which extends into the usual transmission selector mechanismfor causing operation of the, various speed ratio controlling devicesaforesaid. The 35 arrangement illustrated is of the preselector typewhereby the arm i'l may be manipulated to set the transmissionfor thedesired speed ratio, the release of any braking device previouslyengaged and the subsequent engagement of another of the 40 ious speedratio controlling devices according to the setting thereof determined bythe aforesaid adjustment of the selector arm ll.

In operation of the planetary transmission C. as thus far described, theoperator adjusts the selector arm I! to. one of the notches of theselector segment l3 according to the desired speed ratio. setting. Theoperator then depresses I the pedal 33 to release any braking device ofthe transmission which was previously in operation and on release of thepedal 33 a further tra'nsmission controlling device will be actuatedac-' cording to the aforesaid setting ofthe selector arm l1. a Referringnow to the main clutch B which is best illustrated in Fig. 3, the driveto the clutch is provided by the engine, driving shaft 40 and I flywheelll connected thereto. The flywheel ll carries a driving housing '42adapted to drive a pressure plate. 43, the latter being normally urgedtoward the flywheel by a plurality of circumferentially spaced springs44 to apply pressure to the driven friction disc member 45 between thepressure plate and flywheel. The driven disc is shaft 46. The collar 48is movable forwardly to actuate levers 41 by a releasing lever 49carried by a shaft 50 illustrated in Fig. 2 as projecting laterally fromthe clutch housing. The shaft 58 has a collar 5| secured thereto, thelatter having an actuating-bar 52 best shown in Fig. 1, this bar beingselectively operable by either of a pair of levers 53 and 54. I

The lever 58 is provided with a pedal 55 at a position forconvenient'manipulation by the vehicle driver and preferably in closeassociation with the aforesaid pedal 33. Thus, the vehicle driver canrelease the'clutch B by depressing the clutch pedal 55 with his foot,the drive between the engine A and the transmission C being therebyinterrupted.

The collar 5i may be provided with a downwardly extending lever 56connected to a spring 51 to yieldingly urge theshaft 58-to the posiitonillustrated in Fig. 3; The aforesaid lever 54 is connected to a suitablepower actuating device preferably responsivein its actuation to operation of the engine; the illustration showing a vacuum operatingmechanism adapted to release the clutch B whenever the engine throttleis closed or partially closed to produce a partial -vacuum in the intakemanifolding of the engine.

Thus, the lever 54 is connected to a piston rod 58 which extendsforwardly to the vacuum operating cylinder 59, the latter being adaptedto house the piston 69 for causing actuation of the piston rod 58.The-rod 58 actuated by piston 68 ex- I tends rearwardly from cylinder 59through a guide 6| projecting rearwardly from cylinder 59. The engine Ais illustrated as having the usual intake manifold 62 open through aflexible pipe 63 to the port 64 of the valve controlling device 65.Cylinder 59 has a port 66 adapted to communicate with port 64 by way ofthe port 61 in the valve device and the ports 68 69' of the 'slidablyadjustable vacuum control valves 10, 1|

respectively. Cylinder port 68 thus communicat-es with port 64 only whenboth of valves -18, 1i are positioned to align their respective ports68, 69 with ports 64, 61 and 88. Valves 19 and H are respectivelyprovided with vent passages I8 and H I I 4 For the normal operation ofthe piston 68 by vacuum from the engine intake system, the valve 10 isleft in the position illustrated in Fig. 1 although, as will-behereinafter apparent,- this valve may be positioned forwardly to movevalve pert 68 beyond port 64 to prevent the latter fromcommunicating'with cylinder portIl- The-.valve'll controls the supply ofvacuum to cylinder 59 and thus controls the operation of piston 68 andclutch B, this valve being prefer-- ably operably connected to the usualaccelerator I pedal so that when the pedal is-released to close theusualv engine throttle, ,the partial vacuum thus produced in the engineintake system will communicate with cylinder 59 by movement of valve Hto register port 69 with ports 64 and 61.

Thus, valve II is connected through a link 12 to lever 13 fixed torockshaft 14, the latter being rocked by, a second lever I5 fixedthereto and operated by link 16 extending through the usual vehicletoe-board H for connection to the accelerator pedal I8. A tension spring19 tends to yieldingly urge valve H rearwardly to align ports 69 and 64,spring 19 also restoring pedal 18 to its released position for closingthe usual engine comprising, for example, an adjustablevalve 83 adaptedto restrict the flow of air from cylinder through ports 84, 85 andtherebyregulate the speed of rearward movement of piston '68. In orderto accommodate the slight rocking movement of cylinder 59 as rod 58follows the lever 54, the cylindervis pivotally supported at 59 to anengine;bracket 59 The valve '10 is controlledby "a suitable linkage orBowden wire 86 to a handle 8 iassociated with the vehicle dash 88.; Thehandle 81 has a stem 89zprovided with a notch 98-;afdapted to. -receivea spring pressed ball 9; i ;when-jhandle 81(iszpulled outwardly fromdash'88, thisQ movement actuating valve 19 into the 1 positio'n torender the vacuum cylinder 59 in .opera tiver'condition. A second notch92 is engageablewith ball 9| when handle 81 is pushed inwardly to movevalve 19 to ,cut oil. the vacuum supplyto cylinder 59 and thereby renderthe latter ineffective. I

When the piston 68 is moved forwardly by the partial vacuum actingbetween manifold'62, ports 68, 69 and 66, rearward movement of piston 60under action of spring 51 may subsequently readily take place by aforward movement of either of the valves 10 or H venting cylinder 59forwardly of piston 88 by rcason'of the vent passages lil' 'or H .v

Assuming that the valve 18 is positioned as in Fig. 1 to establishcommunication between ports 64 and 66, it will be apparent that when theengine A is operating under closed throttle conditions as in idlingjforexample, the partial vacuum produced in the intake manifold 62 will betransmitted to cylinder 59 by rearward movement of valve H to causeforward movement of the piston rod 59 to release the clutch B. When thethrottle valve of the engine is again opened by depressing theaccelerator pedal 18, the partial vacuum is relieved in cylinder 59 bymovement of valve II to the Fig. 1 position and the piston rod 58 movesrearwardly under the influence of springs 5'1 and 44 to cause smooth en-B is subject to control by reason of the clutch aforesaid conditions,even where the transmission C has one of its speed ratio controllingdevices in actuated or operating condition. The clutch pedal 55 alsoprovides a convenient-means for releasing the clutch B from engine A sothat the latter can be readily started as in cold weather withoutexperiencing any drag from the planetary gear sets of transmission C. r

I desire to. point out that I do not limit my invention, in the broaderaspects thereof, to any particular combination and arrangement of partssuch as shown and described for illustrative purposes, since variousmodifications will be apparent from the teachings of my invention andwithin the scope thereof as defined in the appended claims.

What I claim is:

1. In a motor vehicle power transmission, an engine having an intakeadapted to produce a relatively low pressure during operation thereof,

a planetary gear transmission, a clutch trans-v mitting the drive fromsaid engine to'said trans- -mission, manually operable control means,and.

means for utilizing said low pressure under control of said controlmeans foractuating said clutch.

2. In a motor vehicle power transmission having a plurality of planetarygear sets having rotary controlling elements and devices frictionallyand selectively engageabie with said elements to vary the speed ratiodrive through the transmission, an engine operated driving shaft adaptedto drive the transmission, a clutch between said driving shaft and saidtransmission for con-,

acting to automatically engage and disengage said clutch in response tomanipulation of the motor vehicle engine accelerator pedal. I

.4. In a motor vehicle, an enginehaving a throttle. adiustingmechanism,a planetary gear transmission having a plurality of rotary elements andassociated frictionally engagingspeecl ratio co changing devices, meansfor selectively actuating said devices, clutching means between saidengine and said transmission, power operating means for operating saidclutching means, andmeans actuated in response to operation of saidmechanism, in adjusting the throttle to idle said engine, forcontrolling operation of said power means to disconnect the drive fromthe engine to the transmission, the last 'said means being soconstructed and arranged-as to facilitate, selectivefrictionalengagement of 'saiddeviceswith said rotary ele-,

ments and minimize shock incident thereto in response to manipulation ofsaid selectively actuating means during release of said throttleadjusting mechanism to disengage said clutching means.

5. In a motor vehicle, an engine having a. throttle adjustingmechanism,a planetary gear transmission'having a plurality of rotary elements andassociated frictionally engaging speed ratio changing devices, means forselectively actuating said devices, clutching means between said engineand said transmission, power operating means .for operating saidclutching means, and

means actuated in response to operation of said mechanismgin adjustingthe throttle to idle the engine, for controlling operation of saidpowermeans to disconnect the drive from the engine to the transmission withone of said speed ratio controlling devices in its frictionally engagedcondition, the last said means being so constructed and arranged as tofacilitate selective frictional engagement of said devices and minimizeshock incident thereto in response to manipulation of said selectivelyactuating means during release ofsaid throttle adjusting mechanismto'disengage said clutching means.

6. In a motor vehicle power transmission having a plurality of planetarygear sets having rotary'controlling elements and devices adapted as ffor frictional and selective engagement with said 1 elements to vary thespeed ratio drive through the transmission, manually operable selector-means adapted for manipulation to selectively engage said devices withsaid rotary controlling elements, an engine having a throttle adjustingmechanism, an engine operated driving shaft adapted'to drive thetransmission, a clutch between said driving shaft and said transmissionfor controlling the drive therebetween, and means acting toautomatically engage'and disengage said clutch in response topredetermined operation of said throttle adjusting mechanism duringoperaally-operable selector means during release of said throttleadjusting mechanismto disengage said clutch.

CARL BREER.

